The prior art has evolved a variety of bone staples for use in surgical osteotomy procedures. Such staples conventionally have a pair of staple legs which are driven into the opposing ends of the bone segments which are to be joined together, and a mechanism for forcing the staple legs towards one another, thereby in turn forcing the ends of the bones together. U.S. Pat. No. 3,862,631 issued Jan. 28, 1975 for an invention of Roger Tilston Austin entitled "Surgical Implants" is typical of the prior art. Austin's "implant" takes the form of a staple with first and second legs. The first leg has a threaded projection which may be screwed into a threaded barrel provided on the second staple leg. The threaded projection on the first staple leg is made sufficiently long that it protrudes through the threaded barrel on the second staple leg, thereby facilitating the threaded fastening of a spring washer and a pair of lock nuts on the protruding end of the threaded projection. Once the staple has been driven into the bone, the lock nuts are tightened to draw the staple legs and thus the bone segments together. There are however a number of shortcomings to this arrangement. For example, bone staples are preferably made as small as reasonably practical to avoid undue patient discomfort caused by protrusion of staple components beneath the skin. Accordingly, the lock nuts of the Austin staple are comparatively small; however this makes it difficult to tighten the lock nuts at the surgical site, thus potentially enabling slippage of the bone segments relative to one another, or dislodgement of the staple. Moreover, it is difficult to apply adequate compressive forces between the ends of the bone without stripping the lock nuts. Austin's bone staple also has a relatively high profile. That is, the lock nuts, spring washers, threaded barrel and threaded projection of the staple must all be left protruding above the bone after the staple has been inserted. This can cause considerable patient discomfort and pain.
The present invention overcomes the foregoing disadvantages by providing a bone staple which can be easily manipulated by the surgeon to apply considerable compressive forces between the ends of bone segments joined together with the staple; which is not prone to slippage or dislodgement after placement; and which has a low profile, thus minimizing patient discomfort.